The present invention relates to a method for estimating the magnitude of a back-and-forth-direction force exerted on a pneumatic tire, more particularly to a method capable of estimating the magnitude even if not all of sensors work in order.
A method for estimating the magnitude of a force exerted on a pneumatic tire is disclosed in U.S. Pat. No. 7,249,498, wherein it is described that the magnitude of the force in the back-and-forth-direction can be estimated by the use of one or more strain sensors fixed to the tire sidewall. Indeed, it is possible to estimate the magnitude, but it is based on the premise that all of the sensors work in order.
The most important purpose of estimating the magnitude of the back-and-forth-direction force is to control a brake system of the vehicle, for example so as to construct a well-known anti lock brake system (ABS).
In such a brake system, for safety's sake, it is very important to continue to output the estimated magnitude data toward the brake controller even if not all of the sensors work in order.